Why You Need to Forget Stuff

Forgetting names, faces, or events is a universal human experience; even those who see their minds as steel traps struggle with memory lapses from time to time. Most consider these mental slip-ups to be annoyances at best—at worst, they’re seen as a potentially worrisome sign of cognitive decline.

But neurologist Scott Small, who studies and treats Alzheimer’s disease at Columbia University, thinks this view of forgetting is all wrong. In his upcoming book Forgetting: The Benefits of Not Remembering, Small argues that fading memories aren’t always the scourge we think—in fact, some amount of forgetfulness is critical for our minds and relationships to function at their best. Small spoke with PT about the oft-overlooked upsides of forgetting.

You argue that normal, nonpathological forgetting isn’t a glitch, but rather an adaptation. Why?

If our environments were like Groundhog Day—every day was identical—we would want a perfect memory. But because we live in a noisy, ever-fluctuating world, forgetting details is actually a perfect adaptation. It allows our brains to generalize.

People think, for instance, that if they had a photographic memory, they would remember all faces. And they might recognize all faces in mugshots—but they wouldn’t recognize those faces if they were in a different light, or shaven vs. unshaven, et cetera. Their brain would trip so much on the differences that it would miss the sameness. We need memory—but only if we sculpt it with some forgetting.

How might a photographic memory interfere with creativity?

Creativity isn’t making something out of nothing. It’s making connections between already-known elements—ideas, words, visuals, or memes—to create something new. But to make new connections, the existing connections in your mind have to be loose. If the connections between those elements are too tightly bound in your memory, there’s no room for creativity.

Why are occasional memory lapses good for our social life?

We’re developing drugs to protect against memory loss. But many marital therapists have joked that what they want is a forgetfulness drug. Too much memory presents a challenge in any long-term relationship. Resentment, vindictiveness—they all come from not being able to let go of emotional memories. People who ruminate over anger or fear suffer, often in loneliness.

What can we do to help our brains forget what we need to forget?

One of the best ways to make sure that you don’t have a brain that’s burning too hot with bad memories is to stay socially engaged. PTSD is a disorder of too much memory, and one of the things that most predisposes someone to PTSD after a traumatic event is social isolation.

Another thing to do is sleep, and sleep well. Many experts have concluded that we sleep in order to forget, so it makes sense that sleep has been shown to improve creativity. If you’re sleep-deprived, your brain is on fire with too many memories that haven’t been trimmed. The brain is like a lawn of grass—you need to keep it trimmed to make way for new memories, new connections, and new growth.

LinkedIn image: Michael D Edwards/Shutterstock